CN102848081A - Laser beam applying apparatus - Google Patents

Abstract

The laser light irradiation device provided by the present invention has: a laser light oscillating unit, which oscillates laser light; a condenser lens, which converges the laser light oscillated by the laser light oscillating unit; a diffractive optical element, which is arranged on the laser light oscillating Between the unit and the condensing lens, the point shape of the laser light oscillated by the laser light oscillating unit is specified; The 0th-order light is excluded from the 0th-order light of the light, and only the primary light with a predetermined point shape is introduced into the condenser lens. The 0th-order light exclusion unit has: a first prism having an incident surface and an outgoing surface; A 2 prism, which has a 0-order light reflecting surface and a primary light-emitting surface; and an attenuator, which absorbs the 0-order light reflected on the 0-order light reflecting surface of the second prism.

Description

Laser light irradiation device

technical field

The present invention relates to a laser beam irradiation device for irradiating a laser beam to a workpiece such as a semiconductor wafer or an optical device wafer.

Background technique

In the manufacturing process of semiconductor devices, the surface of a substantially disc-shaped silicon substrate is divided into a plurality of regions by dividing lines called streets arranged in a grid pattern, and devices such as LC and LSI are formed in the divided regions. Then, the region where the semiconductor wafer is cut along the lanes to form devices is divided to manufacture individual semiconductor chips. In addition, the optical device wafer formed by stacking light-receiving elements such as photodiodes and light-emitting elements such as laser diodes on the surface of the sapphire substrate is also cut along the lanes to divide it into individual optical devices such as photodiodes and laser diodes. Applied to electrical equipment.

As a method of dividing the semiconductor wafer and the optical device wafer along the above-mentioned lanes, there is proposed a method of irradiating along the lanes with pulsed laser light having an absorptive wavelength with respect to the wafer to form laser processing grooves, and performing laser processing along the laser processing grooves. disconnect.

In addition, in order to improve the processing accuracy, a laser processing device in which the spot shape of the laser beam is formed into an ellipse has also been proposed. This laser processing device is equipped with a spot shaping unit composed of a cylindrical lens in order to form the spot shape of the laser beam into an ellipse (see, for example, Patent Document 1).

In addition, as a relatively simple method of forming the spot shape of laser light into a predetermined shape, a technology using a diffractive optical element (DOE: Diffractive Optic Element) is known.

[Patent Document 1] Japanese Unexamined Patent Publication No. 2006-289388

However, in the method of forming the spot shape of the laser beam into a predetermined shape using a diffractive optical element, when the primary light is generated by the diffractive optical element and the spot shape of the laser beam is formed into a predetermined shape, the 0th order that is not generated as the primary light The light is also irradiated to the workpiece together with the primary light, and there is a problem that processing performance is lowered.

Contents of the invention

The present invention has been accomplished in view of the above facts, and its main technical task is to provide a device that can generate primary light through a diffractive optical element to form the spot shape of the laser beam into a predetermined shape, and can also eliminate ungenerated primary light. Laser light irradiation device for 0-order light.

In order to solve the above-mentioned main technical problems, the present invention provides a laser light irradiation device, which has: a laser light oscillation unit that oscillates the laser light; a condenser lens that converges the laser light oscillated by the laser light oscillation unit ; a diffractive optical element, which is arranged between the laser light oscillating unit and the condenser lens, and specifies the point shape of the laser light oscillated by the laser light oscillating unit; The element specifies the point shape of the primary light and the 0th order light that is not generated into the primary light, and only the primary light of the specified point shape is excluded to the condenser lens. The 0th order light exclusion unit has: the first A prism, which has an incident surface and an exit surface, the incident surface is a surface on which the primary light and the zero-order light are incident, the exit surface is inclined relative to the incident surface, and the primary light and the zero-order light with an angle relative to the primary light are emitted surface; the second prism, which has a 0th light reflection surface and a primary light exit surface, the 0th light reflection surface is a surface that allows the incident light of the primary light emitted from the exit surface of the 1st prism and reflects the 0th light, The primary light exit surface is a surface for emitting primary light; and an attenuator absorbs the 0-order light reflected on the 0-order light reflection surface of the second prism.

Preferably, the incident surface of the above-mentioned 1st prism is set so that the primary light that passes through the diffractive optical element is vertically incident, the outgoing surface of the 1st prism and the 0th light reflection surface of the 2nd prism are set in parallel, and the 0th order light reflection surface of the 1st prism The incident surface and the outgoing surface of the second prism are set parallel to each other, and the spot shape defined by the diffractive optical element is introduced into the condenser lens in a similar shape. Preferably, the 0-order light reflection surface of the second prism is coated with angle separation.

The laser beam irradiating device of the present invention has: a diffractive optical element disposed between the laser beam oscillating unit and the condensing lens for specifying the point shape of the laser beam oscillated by the laser beam oscillating unit; The 0th-order light is excluded from the primary light whose point shape is specified by the diffractive optical element and the 0th-order light which is not generated into the primary light, and only the primary light with the specified point shape is introduced into the condenser lens. The 0th-order light exclusion unit has: The first prism has an incident surface and an exit surface, the incident surface is a surface on which the primary light and the zero-order light are incident, the exit surface is inclined relative to the incident surface, and the primary light and the zero-order light have an angle relative to the primary light Emerging face; the second prism, which has a 0-order light reflection surface and a primary light-emitting surface, and the 0-order light reflection surface is to allow the incident of the primary light emitted from the exit surface of the 1st prism and reflect the 0-order light Surface, this primary light exit surface is the surface that emits the primary light; and an attenuator, which absorbs the 0th light reflected on the 0th light reflection surface of the second prism, so it can be eliminated by the 0th light exclusion unit that does not generate as Since the zero-order light of the dot-shaped primary light is defined by the diffractive optical element, it is possible to prevent reduction in processing performance due to irradiation of the zero-order light.

Description of drawings

Fig. 1 is a perspective view of a laser processing machine equipped with a laser beam irradiation device according to the present invention.

Fig. 2 is a schematic configuration diagram of a laser beam irradiation device according to the present invention.

Fig. 3 is a perspective view of an optical device wafer as a workpiece.

4 is a perspective view showing a state where the optical device wafer shown in FIG. 3 is attached to the surface of the adhesive tape mounted on the ring frame.

FIG. 5 is an explanatory diagram of a laser processing groove forming step of forming laser processing grooves in the optical device wafer shown in FIG. 3 using the laser processing apparatus shown in FIG. 1 .

Symbol Description

2. Stationary base; 3. Chuck table mechanism; 36. Chuck table; 37. Machining feeding unit; 38. 1st indexing feeding unit; 5. Laser light irradiation unit; 53 Focus point position adjustment unit; 6 Laser light irradiation device; 62 Pulse laser light oscillation unit; 63 Concentrator; 631 Steering mirror; 632 Condenser lens; ; 6340 light exclusion unit; 635 first prism; 636 second prism; 637 attenuator; 7 camera unit; 10 optical device chip; F ring frame; T adhesive tape

Detailed ways

Preferred embodiments of the laser beam irradiation device according to the present invention will be described in detail below with reference to the accompanying drawings.

Fig. 1 shows a perspective view of a laser processing machine equipped with a laser beam irradiation device according to the present invention.

The laser processing machine shown in FIG. 1 has a stationary base 2, and holds a workpiece arranged on the stationary base 2 so as to be movable in the machining feed direction (X-axis direction) indicated by an arrow X. The chuck table mechanism 3, the laser beam arranged on the stationary base 2 so as to be movable in the index feed direction (Y-axis direction) indicated by the arrow Y perpendicular to the processing feed direction (X-axis direction) The irradiation unit support mechanism 4 is disposed on the laser beam irradiation unit support mechanism so as to be movable in the focusing point position adjustment direction (Z-axis direction) shown by the arrow Z perpendicular to the holding surface of the chuck table described later. 4 of the laser light irradiates the unit 5 .

The above-mentioned chuck table mechanism 3 has a pair of guide rails 31, 31 arranged in parallel on the stationary base 2 along the processing feed direction (X-axis direction) indicated by the arrow X, and is movable in the X-axis direction. The first sliding block 32 arranged on the guide rails 31, 31, and the second sliding block 32 arranged on the first sliding block 32 can move in the index feed direction (Y-axis direction) shown by the arrow Y. The slide block 33 , the cover table 35 supported on the second slide block 33 by the cylindrical member 34 , and the chuck table 36 as a workpiece holding means. The chuck table 36 has a suction pad 361 made of a porous material, and a workpiece such as a disc-shaped semiconductor wafer is held on the suction pad 361 as a workpiece holding surface by a suction unit (not shown). The chuck table 36 configured as above is rotated by a pulse motor (not shown) arranged in the cylindrical member 34 . A jig 362 for fixing a ring-shaped frame to be described later is also disposed on the chuck table 36 .

The first slide block 32 has a pair of guided grooves 321, 321 on its lower surface, which are fitted with the pair of guide rails 31, 31, and a pair of guide rails formed parallel to the Y-axis direction on its upper surface. 322, 322. The first slider 32 configured as above is configured to be movable in the X-axis direction along the pair of guide rails 31 and 31 by fitting the guided grooves 321 and 321 into the pair of guide rails 31 and 31 . The chuck table mechanism 3 in the illustrated embodiment has a machining feed unit 37 constituted by a ball screw mechanism for moving the first slide block 32 in the X-axis direction along the pair of guide rails 31 , 31 . The machining feed unit 37 has a drive source such as an externally threaded rod 371 arranged in parallel between the pair of guide rails 31 and 31 , and a pulse motor 372 for rotationally driving the externally threaded rod 371 . One end of the externally threaded rod 371 is rotatably supported on a bearing block 373 fixed on the above-mentioned stationary base 2 , and the other end thereof is transmission-connected to the output shaft of the above-mentioned pulse motor 372 . Furthermore, the externally threaded rod 371 is screwed into a through internally threaded hole formed in a not-illustrated internally threaded block protruding from the lower surface of the center portion of the first slider 32 . Therefore, the externally threaded rod 371 is driven forward and reverse by the pulse motor 372 , so that the first slider 32 moves in the X-axis direction along the guide rails 32 , 32 .

The second slider 33 has a pair of guided grooves 331, 331 on its lower surface, which are fitted with a pair of guide rails 322, 322 provided on the upper surface of the first slider 32. The guide grooves 331, 331 are fitted to the pair of guide rails 322, 322, and are movable in the Y-axis direction. The chuck table mechanism 3 in the illustrated embodiment has a ball screw mechanism for moving the second slide block 33 in the Y-axis direction along the pair of guide rails 322 and 322 provided on the first slide block 32 . The first index feed unit 38 . The first index feeding unit 38 has a driving source such as an externally threaded rod 381 provided in parallel between the pair of guide rails 322 and 322 , and a pulse motor 382 for rotationally driving the externally threaded rod 381 . One end of the externally threaded rod 381 is rotatably supported on a bearing block 383 fixed on the upper surface of the first sliding block 32 , and the other end thereof is drive-connected to the output shaft of the pulse motor 382 . In addition, the externally threaded rod 381 is screwed into a through internally threaded hole formed in a not-illustrated internally threaded block protruding from the lower surface of the center portion of the second slider 33 . Therefore, the second slider 33 moves in the Y-axis direction along the guide rails 322 and 322 by driving the externally threaded rod 381 forward and reverse by the pulse motor 382 .

The supporting mechanism 4 of the above-mentioned laser beam irradiation unit has a pair of guide rails 41, 41 arranged in parallel on the stationary base 2 along the index feed direction (Y-axis direction) shown by arrow Y, so as to be movable in the Y-axis direction. The movable support base 42 arranged on the guide rails 41, 41 in a manner. The movable support base 42 has a movable support portion 421 movably disposed on the guide rails 41 , 41 , and an assembly portion 422 mounted on the movable support portion 421 . A pair of guide rails 423 , 423 extending in the focusing point position adjustment direction (Z-axis direction) indicated by arrow Z is provided in parallel on one side of the mounting portion 422 . The laser beam irradiation unit support mechanism 4 of the illustrated embodiment has a second index feed mechanism composed of a ball screw mechanism for moving the movable support base 42 in the Y-axis direction along the pair of guide rails 41 , 41 . Unit 43. The second index feeding unit 43 has a drive source such as an externally threaded rod 431 arranged in parallel between the pair of guide rails 41 and 41 , and a pulse motor 432 for rotationally driving the externally threaded rod 431 . One end of the externally threaded rod 431 is rotatably supported on an unillustrated bearing block fixed on the stationary base 2 , and the other end thereof is drive-connected to the output shaft of the pulse motor 432 . Furthermore, the externally threaded rod 431 is screwed into a female threaded hole formed in a not shown female threaded block protruding from the lower surface of the central portion of the movable support base 42 . Therefore, the externally threaded rod 431 is driven forward and reverse by the pulse motor 432 , so that the movable support base 42 moves in the Y-axis direction along the guide rails 41 , 41 .

The laser beam irradiation unit 5 has a unit holder 51 and the laser beam irradiation device 6 attached to the unit holder 51 . The unit holder 51 is provided with a pair of guided grooves 511 slidably fitted to the pair of guide rails 423 , 423 provided on the mounting portion 422 , and the guided grooves 511 are fitted to the guide rails 423 , 423 . Therefore, it is supported so as to be movable in the direction (Z-axis direction) of focusing point position adjustment indicated by arrow Z.

The laser beam irradiation unit 5 has a focusing point position adjustment unit 53 for moving the unit holder 51 along the pair of guide rails 423, 423 in the direction perpendicular to the workpiece holding surface of the chuck table 36, that is, in the Z-axis direction. . The focal point position adjustment unit 53 is constituted by a ball screw mechanism similarly to the processing feed unit 37 , the first index feed unit 38 , and the second index feed unit 43 described above. The focusing point position adjustment unit 53 has a drive source such as an externally threaded rod (not shown) disposed between the pair of guide rails 423, 423, a pulse motor 532 for rotationally driving the externally threaded rod, and the like. The pulse motor 532 drives the externally threaded rod not shown in the forward and reverse directions, so that the unit holder 51 and the laser beam irradiation device 6 move along the guide rails 423 and 423 in the direction of adjusting the spot position indicated by the arrow Z. Furthermore, in the illustrated embodiment, the laser beam irradiation device 6 is moved upward by driving the pulse motor 532 forward, and the laser beam irradiation device 6 is moved downward by driving the pulse motor 532 in reverse.

The laser beam irradiation device 6 has a cylindrical housing 61 fixed to the unit holder 51 and extending substantially horizontally. An imaging unit 7 for detecting a processing area to be laser processed by the above-mentioned laser beam irradiation device 6 is arranged at the front end portion of the cylindrical housing 61 . The imaging unit 7 has an illumination unit for illuminating the workpiece, an optical system for capturing the area illuminated by the illumination unit, an imaging device (CCD) for imaging the image captured by the optical system, etc., and sends the captured image signal to the Control unit shown.

As shown in FIG. 2 , the laser beam irradiation device 6 has a pulsed laser beam oscillating unit 62 arranged in the housing 61 and oscillates a pulsed laser beam LB. The pulsed laser beam oscillated by the pulsed laser beam oscillating unit 62 is The light collector 63 converges and irradiates the workpiece W held on the chuck table 36 described above. The above-mentioned pulsed laser light oscillating unit 62 includes a pulsed laser oscillator 621 composed of a YAG laser oscillator or a YVO4 laser oscillator, and a repetition rate setting unit 622 attached to the pulsed laser oscillator 621 . The pulsed laser oscillator 621 oscillates the pulsed laser beam LB at a predetermined frequency set by the repetition rate setting unit 622 . The repetition frequency setting unit 622 sets the repetition frequency of the pulsed laser light oscillated by the pulsed laser oscillator 621 .

The above-mentioned concentrator 63 has a front end mounted on the housing 61, and directs the pulsed laser light LB oscillated by the above-mentioned pulsed laser light oscillating unit 62 downward in FIG. Direction) A turning mirror 631 for turning the direction, a condenser lens 632 for condensing the laser light whose direction has been changed by the turning mirror 631 and irradiating it to the workpiece W held on the chuck table 36, and a pulsed laser beam oscillation unit Between 62 and the condenser lens 632, a diffractive optical element (DOE: Diffractive Optic Element) 633 that defines the point shape of the pulsed laser beam LB oscillated by the pulsed laser beam oscillating unit 62, and defines a point shape from the diffractive optical element 633 The 0-order light is excluded from the primary light and the 0-order light not generated into the primary light, and only the primary light having a predetermined spot shape is guided to the 0-order light exclusion unit 634 of the condensing lens 632 .

The diffractive optical element 633 is configured such that the pulsed laser beam LB oscillated by the pulsed laser beam oscillating unit 62 has a circular cross-section (spot shape) having an elliptical spot shape S1 in the illustrated embodiment. The diffractive optical element 633 configured as above divides the pulsed laser beam LB oscillated by the pulsed laser beam oscillating unit 62 with a spot shape of a circle S1 into the primary beam LB1 having a spot shape defined as an ellipse S2 and the primary beam LB1 not generated as the primary beam LB1. The zero-order light LB0 enters the zero-order light exclusion unit 634 with a predetermined angle α between them.

The above-mentioned zero-order light exclusion unit 634 has: a first prism 635, which has an incident surface 635a that is incident by the primary light LB1 and the zero-order light LB0, is inclined to the incident surface 635a, and has an angle between the primary light LB1 and the primary light LB1. The exit surface 635b of the 0th order light LB0 exiting; The second prism 636, it has the 0th order light reflection surface 636a that allows the primary light LB1 incident and reflects the 0th order light LB0 from the exit surface 635b of the first prism 635; the primary light emission surface 636 b of the primary light LB1 ; and the attenuator 637 that absorbs the zero-order light LB0 reflected on the zero-order light reflection surface 636 a of the second prism 636 . The incident surface 635 a of the first prism 635 is set so that the primary light LB1 passing through the diffractive optical element 633 is vertically incident. In addition, the outgoing surface 635b of the first prism 635 and the zero-order light reflection surface 636a of the second prism 636 are set to be parallel to each other at a distance s, and formed at an angle β with respect to the incident surface 635a of the first prism 635 . And this angle β is set to use the 0th order light reflection surface 636a of the 2nd prism 636 to reflect the 0th order light LB0 that is emitted from the exit surface 635b of the first prism 635, allowing the primary light LB0 to exit from the exit surface 635b of the first prism 635. The angle at which the light LB1 is incident on the second prism 636 . In addition, the 0th-order light reflection surface 636a of the second prism 636 is coated with an angle separation so as to reflect one 0th-order light LB0 having a small angle difference and make the other primary light LB1 incident. As the angle separation coating agent, MgF 2 , polyethylene terephthalate (PET), cellulose triacetate (TAC), or the like can be used. Furthermore, the incident surface 635a of the first prism 635 and the outgoing surface 636b of the second prism are set to be parallel. The 0th-order light exclusion unit 634 configured as above reflects the 0th-order light LB0 passing through the diffractive optical element 633 by the 0th-order light reflection surface 636 a of the second prism 636 , and guides it to the attenuator 637 . On the other hand, the zero-order light exclusion unit 634 guides the primary light LB1 whose point shape is defined as an ellipse S2 by the diffractive optical element 633 to the above-mentioned condenser lens 632 in a similar shape S3. The primary light LB1 having an elliptical spot shape S3 introduced into the condenser lens 632 as described above is condensed by the condenser lens 632 and irradiates the workpiece W held on the chuck table 36 as an elliptical spot S4 .

The laser processing machine of the illustrated embodiment is configured as above, and its operation will be described below. FIG. 3 shows a perspective view of an optical device wafer as a workpiece processed by the above-mentioned laser processing machine. In the optical device wafer 10 shown in FIG. 3 , for example, a light emitting layer (epitaxial layer) 110 , which is an optical device layer, made of a nitride semiconductor with a thickness of 5 μm is laminated on the surface of a sapphire substrate with a thickness of 100 μm. Further, optical devices 112 such as light emitting diodes and laser diodes are formed in a plurality of regions of the light emitting layer (epitaxial layer) 110 divided by a plurality of streets 111 formed in a grid pattern.

When laser processing the optical device wafer 10 along the partition lanes 111 using the above-mentioned laser processing machine, the optical device wafer 10 is attached to the surface of the adhesive tape mounted on the ring frame. That is, as shown in FIG. 4 , the back surface 10 b side of the optical device wafer 10 is attached to the surface of the adhesive tape T attached to the ring frame F (wafer attachment step). Therefore, in the optical device wafer 10 attached to the surface of the adhesive tape T attached to the annular frame F, the surface 10 a becomes the upper side.

After the above-mentioned wafer attaching step is performed, the adhesive tape T to which the optical device wafer 10 is attached is placed on the chuck table 36 of the laser processing apparatus shown in FIG. 1 above. Then, the optical device wafer 10 is sucked and held on the chuck table 36 via the adhesive tape T by activating a suction unit (not shown) (wafer holding step). Therefore, the surface 10 a becomes the upper side of the optical device wafer 10 sucked and held by the chuck table 36 . Furthermore, the ring frame F on which the adhesive tape T to which the optical device wafer 10 is attached is fixed by the jig 362 arranged on the chuck table 36 . As described above, the chuck table 36 holding the optical device wafer 10 is positioned directly below the imaging unit 7 by the process feeding unit 37 .

When the chuck table 36 is positioned directly below the imaging unit 7 , an alignment operation is performed to detect a processing area of the optical device wafer 10 to be laser processed by the imaging unit 7 and a control unit not shown. That is, the image pickup unit 7 and the control unit (not shown) execute the laser light irradiation device 63 of the laser beam irradiation device 6 for executing the street 111 formed in a predetermined direction of the optical device wafer 10 and irradiating the laser beam along the street 111. Image processing such as pattern matching for position alignment between laser beams to complete the alignment of the irradiation position of the laser light (alignment step). In addition, the alignment of the irradiation position of the laser beam is similarly completed for the streets 111 formed on the optical device wafer 10 in the direction perpendicular to the above-mentioned predetermined direction.

When the spacer lanes 111 formed on the surface 10a of the optical device wafer 10 adsorbed and held on the chuck table 36 are detected as described above, and the laser beam irradiation position is aligned, the processing feed unit 37 and the first index feed unit 38 are activated. , as shown in Figure 5(a), move the chuck table 36 to the laser beam irradiation area where the concentrator 63 of the laser beam irradiation device 6 is located, and place one end of the specified interval road 111 (in Figure 5(a) left end) is positioned directly below the light collector 63 of the laser beam irradiation device 6 . Next, start the laser beam irradiation device 6, irradiate pulsed laser beams with a wavelength that is absorbing to the sapphire substrate constituting the optical device wafer 10 from the concentrator 63, and move the chuck table 36 along the direction of the figure at a predetermined feed speed. 5(a) moves in the direction indicated by the arrow X1 (laser processing groove formation step). And, as shown in FIG. 5( b ), when the other end (the right end in FIG. 5( b )) of the predetermined interval track 111 reaches directly below the light collector 63 , the irradiation of the pulsed laser beam is stopped and the card is stopped. Movement of the disc table 36. In this laser processing groove forming step, the converging point P of the pulsed laser beam is aligned with the vicinity of the upper surface of the optical device wafer 10 . As a result, laser-processed grooves 120 are formed along the streets 111 on the optical device wafer 10 .

For example, the processing conditions in the above laser processing groove forming step are set as follows.

Light source: YAG pulsed laser

Wavelength: 355nm

Repetition frequency: 10kHz

Average output: 3.5W

Focus spot diameter: ellipse with minor axis 10μm and major axis 200μm

Processing feed speed: 100mm/sec

As described above, after performing the above-mentioned laser machining groove forming step along all the streets 111 formed in the first direction of the optical device wafer 10, the chuck table 36 holding the optical device wafer 10 is positioned at a position rotated by 90 degrees. location. Then, the laser machining groove forming step is performed along all the streets 111 formed in the second direction perpendicular to the first direction of the optical device wafer 10 .

In the laser machining groove forming step described above, the laser beam irradiated on the optical device wafer 10 makes the dot shape into an ellipse by the diffractive optical element 633 as above, thus forming the laser machining groove 120 with high machining accuracy. Also, since the zero-order light discharge unit 634 excludes the zero-order light LB0 that is not generated as the primary light LB1 defined by the diffractive optical element 633 in the shape of an elliptical point, it is possible to prevent reduction in processing performance due to irradiation of the zero-order light.

As described above, the optical device wafer 10 subjected to the step of forming laser-processed grooves along all the streets 111 is transferred to the step of dividing the wafer along the streets 111 in which the laser-processed grooves 120 are formed.

Claims (3)

1. laser beam irradiation apparatus, it has:

The laser beam oscillating unit, its laser beam that vibrates;

Collector lens, it is assembled the laser beam that vibrated by this laser beam oscillating unit;

Diffraction optical element, it is equipped between this laser beam oscillating unit and this collector lens, stipulates the vibrate some shape of the laser beam that of this laser beam oscillating unit; And

0 light rejected unit, it is got rid of 0 light and only will stipulate that the once light of putting shape imports to this collector lens from the once light of having been stipulated the some shape by this diffraction optical element and 0 light not being generated as once light,

This 0 light rejected unit has:

The 1st prism, it has the plane of incidence and exit facet, and this plane of incidence is once the face of light and 0 light incident, and this exit facet is to tilt and light and with respect to the face of angled 0 the light outgoing of light tool once once with respect to this plane of incidence;

The 2nd prism, it has 0 light reflection surface and light exiting surface once, this 0 light reflection surface is to allow from the incident of the once light of this exit facet outgoing of the 1st prism and reflect the face of 0 light, this once the light exiting surface be the once face of light of outgoing; And

Attenuator, it absorbs 0 light that this 0 light reflection surface at the 2nd prism reflects.

2. laser beam irradiation apparatus according to claim 1, wherein, this plane of incidence of the 1st prism is set to and makes the vertically incident of once light of having passed through this diffraction optical element, this 0 light reflection surface of this exit facet of the 1st prism and the 2nd prism is set abreast, this plane of incidence of the 1st prism and this exit facet of the 2nd prism are set abreast, and the some shape of being stipulated by this diffraction optical element imports to this collector lens with similar shape.

3. laser beam irradiation apparatus according to claim 1 and 2 wherein, has been implemented the angular separation coating to this 0 light reflection surface of the 2nd prism.

Images